1. Field
This invention is directed to systems and methods for an image processing system that improve the quality of line edges for rendering.
2. Description of Related Art
Scanners and other types of image capture devices, and digital copiers and other image forming devices, have become ubiquitous office productivity tools for generating electronic images of physical original documents or generating physical copies of electronic images. Once an electronic image has been generated, either from scratch or from a physical original document, the electronic image data can be used in an infinite variety of ways to increase the productivity and the product quality of an office. Image capture devices include desktop scanners, other stand alone scanners, digital still cameras, digital video cameras, the scanning input portions of digital copiers, facsimile machines and other devices that are capable of generating electronic image data from an original document, and the like. These image capture devices can also include image databases that store previously captured electronic image data. Image forming devices may include digital copiers, laser printers, ink jet printers, color ink jet printers, and the like.
As the costs of these various image capture devices and image forming device have dropped and the output quality of the physical copies and the captured electronic image data has improved, these image capture devices and image forming devices have been provided with an ever increasing number of controllable features. Similarly, as users have become comfortable with capturing and using electronic image data obtained from original documents to create physical copies, the uses to which the electronic image data has been put, and thus the needed control over the quality and appearance of the electronic image data and the physical copies, have expanded greatly.
In order to achieve high quality from a scanned image when rendering the image for printing on a device, such as, for example, a color xerographic printer, rendering tags or identifiers that direct the use of different rendering modes, for example, different screen frequencies, may be utilized to optimally reproduce the various features in the image. Since there is no accepted standard for what tags to use, image processing electronics must be resident in the output device or printer to examine the image and generate a useful set of rendering tags to be used when printing the image. Another approach is to use an encoding known as Multiple Raster Content (MRC) wherein different parts of the scanned image are stored as separate objects or layers with different representations, for example, binary for text and line art and contone for image data. In order to achieve high quality at the printer for text and line art, it is desirable to encode the text and line art at high resolution, for example, even at a resolution higher than that of the printer. ITU-T Recommendation T.44 document, published by the Telecommunication Standardization Sector of the International Telecommunication Union, for example, illustrates Mixed Raster Content.